FIGS. 12 and 13 (see Japanese Patent Application Kokai No. H7-302653) show an example of a conventional electrical connector 101. The electrical connector 101 comprises a tine plate 130 having a construction which is such that solder 142 sufficiently rises into through-holes 141a, 141b, 141c, and 141d in a circuit board 140 when the tines 122a, 12b, 122c, and 122d of contacts 120a, 120b, 120c, and 120d are soldered to the circuit board 140 via the tine plate 130. As shown in FIG. 12, the electrical connector 101 comprises an insulating housing 110 that extends in a direction of length (a direction perpendicular to a plane of the page in FIG. 12), the contacts 120a, 120b, 120c, and 120d that are secured to the housing 110 in four rows in a vertical direction, and the tine plate 130. The contacts 120a, 120b, 120c, and 120d in the four rows respectively comprise contact members 121a, 121b, 121c, and 121d that are fastened to the housing 110 that make contact with mating contacts (not shown in the figures), and tines 122a, 122b, 122c, and 122d. The tines 122a, 122b, 122c, and 122d extend from the contact members 121a, 121b, 121c, and 121d toward a rear of the housing 110 (a direction opposite of a mating surface, i.e., rightward in FIG. 12) and then are bent downward at a right angle. The tines 122a of the contacts 120a in a first row from a bottom of the housing 110 are designed such that the portions of the tines 122a that are bent at a right angle are positioned on an innermost side (leftmost side in FIG. 12 and on the side close to the housing 110) of the housing 110 and are respectively inserted into the through-holes 141a in a first row of the circuit board 140 that are located on the innermost side (leftmost side in FIG. 12 and on the side close to the housing 110) of the housing 110 and are respectively connected by soldering to a conductor layer on inner surfaces of the through-holes 141a. Moreover, the tines 122b of the contacts 120b in a second row from the bottom are designed such that the portions of the tines 122b that are bent at a right angle are located in a second position from the inside and that the tines 122b are respectively inserted into the through-holes 141b in a second row of the circuit board 140 that are located in the second position from the inside and are respectively connected by soldering to a conductor layer on the inner surfaces of the through-holes 141b. In addition, the tines 122c of the contacts 120c in a third row from the bottom are designed such that the portions of the tines 122c that are bent at a right angle are located in a third position from the inside and that the tines 122c are respectively inserted into the through-holes 141c in a third row of the circuit board 140 that are located in the third position from the inside and are respectively connected by soldering to a conductor layer on the inner surfaces of the through-holes 141c. Likewise, the tines 122d of the contacts 120d in a fourth and uppermost row are designed such that the portions of the tines 122d that are bent at a right angle are positioned on an outermost side and that the tines 122d are respectively inserted into the through-holes 141d in a fourth row of the circuit board 140 and are located on the outermost side and are respectively connected by soldering to a conductor layer on the inner surfaces of the through-holes 141d. 
The tine plate 130 is constructed from a substantially rectangular plate that extends in the direction of length of the housing 110 and has through-holes 131a, 131b, 131c, and 131d in four rows formed in positions corresponding to the through-holes 141a, 141b, 141c, and 141d in the circuit board 140. Moreover, tapered members 132a, 132b, 132c, and 132d for easily guiding the respective tines 122a, 122b, 122c, and 122d into the through-holes 131a, 131b, 131c, and 131d are provided in the through-holes 131a, 131b, 131c, and 131d on a side of the insertion of the tines. In addition, once the tines 122a, 122b, 122c, and 122d are inserted into the through-holes 131a, 131b, 131c, and 131d in the tine plate 130, the tines 122a, 122b, 122c, and 122d can be respectively aligned with the through-holes 141a, 141b, 141c, and 141d in the circuit board 140.
Projections 132 that extend in the direction of length are respectively provided on an undersurface of the tine plate 130 on an inside of the through-holes 131a in the first row from the inside (on a side close to the housing 110), between the through-holes 131b in the second row from the inside and the through-holes 131c in the third row from the inside, and on the outside of the through-holes 131d in the fourth row on the outermost side. As a result, when the electrical connector 101 is mounted on the circuit board 140 by respectively inserting the tines 122a, 122b, 122c, and 122d into the through-holes 131a, 131b, 131c, and 131d in the tine plate 130, and respectively inserting the tines 122a, 122b, 122c, and 122d protruding from the undersurface of the tine plate 130 into the through-holes 141a, 141b, 141c, and 141d in the circuit board, the projections 132 contact an upper surface of the circuit board 140. This creates a step difference between the upper surface of the circuit board 140 and the undersurface of the tine plate 130, and the through-holes 131a, 131b, 131c, and 131d are positioned in a portion of the lower step. Consequently, a gap is created between the tine plate 130 and the circuit board 140 where the through-holes 131a, 131b, 131c, and 131d are formed in the tine plate 130.
Then, when the tines 122a, 122b, 122c, and 122d are connected by soldering to the through-holes 141a, 141b, 141c, and 141d in the circuit board 140 in a subsequent soldering process, if a reverse side of the circuit board 140 that is mounted on the electrical connector 101 is exposed to a molten solder jet, a capillary action occurs in each of the through-holes 141a, 141b, 141c, and 141d because of the existence of appropriate space inside the through-holes 141a, 141b, 141c, and 141d between the inner walls and the tines 122a, 122b, 122c, and 122d. Accordingly, as is shown in FIG. 13, the solder 142 that is in a molten state moves up inside each of the through-holes 141a, 141b, 141c, and 141d in the circuit board 140 to the upper surface of the circuit board 140 due to the capillary action. The solder 142 further draws up each of the tines 122a, 122b, 122c, and 122d from the upper surface of the circuit board 140 due to the surface tension, and a tip end of the solder 142 in each of the through-holes 141a, 141b, 141c, and 141d forms a fillet 143 that reaches near the tine plate 130. However, the following problem has been encountered in the electrical connector 101. Specifically, the tine plate 130 is designed such that a gap is created between the undersurface of the tine plate 130 and the upper surface of the circuit board 140 by making the plate thickness smaller (thinner) in all portions having the through-holes 131a, 131b, 131c, and 131d; therefore, the surface area of the portions of the tine plate 130 where the gap is created from the circuit board 140 occupies most of the total surface area, creating a problem in that the mechanical strength is insufficient. In particular, when the electrical connector 101 comprising the tine plate 130 is mounted on a circuit board used for an automobile engine control unit, the electrical connector 101 is subjected to a large temperature difference and vibration during use, so that the mechanical strength of the tine plate 130 becomes a problem.